1. Field of the Invention
The present invention relates to pads of flexible sheets and to a method for making these pads. The invention most particularly relates to stacked, adhered pads of sheets which are adhesively secured to each other but have little or no adhesive property to other surfaces when individual sheets are removed from the pad.
2. Background of the Art
Pads of flexible paper sheets, often called scratch pads or writing pads, have long been available in various numbers of sheets, and in different configurations including rectangular, round, oval, regular, irregular, and other peripheral shapes. The sheets in such pads can, optionally, be printed with lines, pictures, persons, companies or corporations, or which can provide a form to be used by a person or a business.
These pads are often made by forming large master sheets that are either printed or unprinted, assembling the master sheets together into a master pad with a stiff back sheet as the bottom most sheet, cutting a plurality of pads of a desired size from the master pad through the use of a shear or die, and then applying a padding compound (e.g., a water or organic solvent based padding compound or a hot melt adhesive padding compound) along edge surfaces of the pads to secure the individual sheets into a secured pad. Individual sheets can then be removed from the tops of the pads by peeling them away from the padding compound. In some such pads (typically with a large amount of sheets that from a pad generally in the shape of cube ) graphics for purposes such as advertising or decoration are printed along exposed edges of the sheets in the pad and along the padding compound adhering the sheets in the pad together. Such printing will have a different appearance along the padding compound than along the edges of the sheets, which can be undesirable.
Pads of flexible paper sheets having bands of repositionable pressure sensitive adhesive on major surfaces adjacent edges of the sheets that adhere the sheets together in the pads have been available for some time under the trade name "Post-it" (TM) brand notes from Minnesota Mining and Manufacturing Company, St. Paul, Minn. Such pads are available with the bands of repositionable pressure sensitive adhesive along all edges of the sheets which are positioned at one side surface of the stack. Additionally, such pads are available with the band of repositionable pressure sensitive adhesive on each successive sheet in the pad along an opposite side surface of the pad as is taught in U.S. Pat. No. 4,781,306 (Smith). This latter pad structure facilitates dispensing of the sheets of such pads from dispensers of the types described in U.S. Pat. No. 4,781,306 (Smith), U.S. Pat. No. 4,653,666 (Mertens), and U.S. Pat. No. 5,080,255 (Windorski). Pads of either of those types can have graphics printed on the edges of the sheets along all of their side surfaces and those graphics can have a similar appearance on all sides of the pad. Providing the band of repositionable pressure sensitive adhesive on the sheets in such a pad adds expense to the pad, however, and for some purposes that band of repositionable pressure sensitive adhesive on sheets removed from the pad is not needed, or can even be undesirable. For example, when notes are to be written on sheets and carried in a pocket or wallet, the repositionable pressure sensitive adhesive, and especially a stronger pressure sensitive adhesive, causes the sheet to adhere to surfaces or pick up stray matter and become dirty.